110kV Oil-Immersed Transformer Supplier — Capacity Range from 6300 to 63000 kVA with Factory Direct Pricing

Time：2026-05-26    Auther：ZTelec-www.ztelectransformer.com

With the continuous expansion of global power grid upgrades, renewable energy integration, and industrial infrastructure development, the demand for 110kV oil-immersed transformers is growing rapidly. Whether for urban distribution network modernization, large industrial parks, wind farms, photovoltaic power stations, or energy storage booster substations, 110kV oil-immersed transformers remain one of the most critical pieces of equipment in modern transmission and distribution systems.

For buyers, EPC contractors, and power engineering companies, selecting a reliable 110kV transformer supplier, obtaining genuine factory pricing, controlling procurement costs, and ensuring equipment quality are essential for project success. Especially for large-capacity transformers ranging from 6300kVA to 63000kVA, the supplier’s manufacturing capability, engineering expertise, and delivery performance directly impact project schedules and operational reliability.

This article provides a comprehensive overview of 110kV oil-immersed transformer capacity classifications, factory direct supply advantages, supplier evaluation standards, key technical parameters, and procurement considerations to help you make efficient and professional transformer purchasing decisions.

110kV Oil-Immersed Transformer Capacity Range

Common Standard Capacity Ratings

According to GB/T 6451 standards and common utility engineering practices, 110kV oil-immersed transformers typically follow the R10 preferred number series. Different capacities are suitable for different transmission and distribution applications.

Rated Capacity	Typical Applications
6300 kVA	Small industrial substations and rural grid upgrades
8000 kVA	Medium-sized industrial parks and commercial complexes
10000 kVA	Main transformers for industrial zones and urban distribution networks
16000 kVA	Urban district power distribution and medium industrial users
20000 kVA	Large factories and renewable energy booster substations
31500 kVA	Main transformers for urban 110kV substations
40000 kVA	Large industrial bases and data center campuses
50000 kVA	Regional 110kV hub substations
63000 kVA	Heavy industrial zones and large renewable energy collection stations

Low-Voltage Side Configuration

The low-voltage side of 110kV oil-immersed transformers is commonly configured as 10kV, 35kV, or 6.3kV, depending on the user’s distribution system requirements. Both two-winding and three-winding transformer designs are available.

Among them, 110/35/10kV three-winding transformers are widely used in regional substations and renewable energy collection stations because they can simultaneously support multiple voltage levels and improve grid flexibility.

Core Advantages of Factory Direct Procurement

Lower Procurement Costs

Traditional transformer procurement often involves multiple intermediary levels, including manufacturers, provincial distributors, regional agents, and local resellers. Each level adds additional profit margins to the final equipment price.

For a 31500kVA/110kV oil-immersed transformer, the price difference between factory direct supply and market distribution channels may reach hundreds of thousands of RMB.

Factory direct procurement helps buyers:

Obtain genuine ex-factory pricing directly;

Reduce intermediary markup costs;

Access bulk order discounts;

Lower the total investment cost of large-scale projects.

More Efficient Technical Communication

Through factory direct cooperation, buyers can communicate directly with transformer design engineers regarding:

High-altitude derating solutions;

Adaptation for high-temperature and high-humidity environments;

On-load tap changer (OLTC) and off-circuit tap changer configurations;

Low-loss S13, S15, or S20 energy-saving designs;

Special impedance, voltage ratio, and vector group requirements.

Direct communication with the manufacturing factory helps reduce technical misunderstandings and improves engineering matching efficiency.

Transparent and Controllable Production Schedule

The manufacturing cycle of large 110kV oil-immersed transformers is typically between 60 and 120 days. Through factory direct procurement, buyers can track production schedules, raw material preparation, and testing progress in real time.

This transparency is especially important for renewable energy projects, substation expansion works, and industrial power distribution upgrades with tight construction schedules.

How to Choose a Reliable 110kV Transformer Supplier

Qualifications and Certification System

When selecting a 110kV oil-immersed transformer supplier, buyers should prioritize verification of the following certifications:

Power equipment manufacturing license;

110kV and above transformer type test reports;

ISO 9001 quality management certification;

ISO 14001 environmental management certification;

CNAS or CMA accredited laboratory test reports.

Suppliers with proven delivery records for State Grid or Southern Power Grid projects generally demonstrate stronger quality control and project execution capabilities.

Core Manufacturing Capability Evaluation

High-quality 110kV transformer suppliers usually possess complete large transformer manufacturing capabilities, including:

High-precision core stacking equipment;

Large winding production lines;

Vacuum drying systems;

Automated tank welding technology;

Comprehensive high-voltage testing facilities.

For core materials, leading manufacturers typically use high magnetic permeability and low-loss cold-rolled silicon steel sheets to reduce no-load losses and improve operating efficiency.

Engineering Project Experience

Buyers should focus on suppliers’ project references over the past three to five years, especially in:

State Grid projects;

Renewable energy booster substations;

Large industrial park substations;

Data center power systems;

Overseas EPC transmission and distribution projects.

Strong engineering experience indicates that the supplier can better manage product quality, transportation arrangements, and on-site installation and commissioning processes.

6300kVA to 63000kVA Technical Parameters and Reference Pricing

Main Technical Parameter Range

The following table shows typical technical parameters for 110kV oil-immersed transformers with S13 energy efficiency level and two-winding structure:

Rated Capacity	No-Load Loss (kW)	Load Loss (kW)	No-Load Current (%)	Approximate Weight (t)
6300 kVA	7–9	40–50	≤0.8	18–22
10000 kVA	10–13	58–70	≤0.7	25–30
20000 kVA	17–21	100–120	≤0.6	42–50
31500 kVA	24–30	148–175	≤0.5	60–72
50000 kVA	35–43	216–255	≤0.5	88–105
63000 kVA	42–52	260–305	≤0.4	108–130

Factory Direct Reference Pricing

The following table shows approximate factory direct prices from mainstream domestic 110kV oil-immersed transformer manufacturers (tax included, transportation excluded):

Rated Capacity	Reference Factory Price (RMB 10,000)
6300 kVA	90–130
10000 kVA	130–180
16000 kVA	175–240
20000 kVA	210–290
31500 kVA	300–420
40000 kVA	380–520
50000 kVA	460–630
63000 kVA	560–760

Prices are heavily influenced by fluctuations in copper, silicon steel, and other raw material markets. Actual quotations should be confirmed directly with the manufacturer.

Products from state-owned enterprise brands and suppliers qualified for ultra-high-voltage projects are typically priced 20% to 40% higher than ordinary brands.

110kV Transformer Procurement Process and Precautions

Standard Procurement Process

The procurement of large 110kV oil-immersed transformers usually includes the following key stages:

Clarifying technical specifications and operating conditions;

Requesting quotations from multiple factories;

Comparing loss values, delivery schedules, and testing configurations;

Conducting factory audits;

Signing detailed technical agreements;

Arranging production supervision and factory test witnessing;

Confirming transportation and installation plans.

Procurement Risk Warnings

During actual procurement, buyers should pay close attention to the following risks:

Low-price products may contain reduced copper usage;

Some manufacturers may use lower-grade silicon steel sheets;

Energy efficiency ratings may be overstated;

The authenticity of type test reports must be verified;

Transportation conditions for large transformers must be confirmed in advance.

For critical infrastructure projects, it is recommended to involve third-party inspection agencies or owner technical teams in supervising key manufacturing stages.

Projects Suitable for Factory Direct Procurement

Factory direct procurement is especially suitable for:

Large substation construction projects;

Renewable energy wind and solar booster substations;

Long-term industrial park expansion projects;

Overseas EPC transmission and distribution projects;

Users requiring long-term spare parts and after-sales support.

For projects with large procurement budgets, factory direct purchasing not only reduces equipment costs but also improves delivery efficiency and long-term technical support quality.

110kV oil-immersed transformers are critical components of modern transmission and distribution systems. Products ranging from 6300kVA to 63000kVA can meet the majority of requirements for industrial power grids, urban distribution networks, renewable energy projects, and large infrastructure developments.

Choosing a factory direct supplier with complete certifications, mature manufacturing processes, stable production capability, and transparent pricing systems helps reduce procurement costs while ensuring transformer quality and project delivery schedules.

Before placing an order, buyers are strongly advised to complete supplier qualification verification, factory inspections, technical agreement reviews, and type test report confirmation to ensure they obtain high-quality 110kV oil-immersed transformers that fully meet project requirements.

Quick Inquiry Guide

To obtain a more accurate quotation for a 110kV oil-immersed transformer, it is recommended to prepare the following technical information in advance:

Rated capacity and purchase quantity;

High-voltage and low-voltage side voltage ratings;

Required vector group;

OLTC or off-circuit tap changer requirements;

Installation site altitude and ambient temperature;

Required energy efficiency level;

Expected delivery time and installation location.